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131.
We define and compute a boundary kernel for local polynomial regression, We prove that the new kernel provides improvement over the existing kernels, Simulations show the improvement in finite samples. 相似文献
132.
This article considers the second-order response surface model in which the experimental units, i.e., plots experience the neighbor effects from immediate left and right neighboring plots assuming the plots to be placed adjacent linearly with no gaps. Conditions have been derived for the estimation of coefficients of second-order response surface model. A method of constructing designs for fitting second-order response surface in the presence of neighbor effects has been developed. The designs so obtained are found to be rotatable. 相似文献
133.
The joint models for longitudinal data and time-to-event data have recently received numerous attention in clinical and epidemiologic studies. Our interest is in modeling the relationship between event time outcomes and internal time-dependent covariates. In practice, the longitudinal responses often show non linear and fluctuated curves. Therefore, the main aim of this paper is to use penalized splines with a truncated polynomial basis to parameterize the non linear longitudinal process. Then, the linear mixed-effects model is applied to subject-specific curves and to control the smoothing. The association between the dropout process and longitudinal outcomes is modeled through a proportional hazard model. Two types of baseline risk functions are considered, namely a Gompertz distribution and a piecewise constant model. The resulting models are referred to as penalized spline joint models; an extension of the standard joint models. The expectation conditional maximization (ECM) algorithm is applied to estimate the parameters in the proposed models. To validate the proposed algorithm, extensive simulation studies were implemented followed by a case study. In summary, the penalized spline joint models provide a new approach for joint models that have improved the existing standard joint models. 相似文献
134.
OLE F. CHRISTENSEN MORTEN FRYDENBERG JENS L. JENSEN JØRGEN G. PEDERSEN 《Scandinavian Journal of Statistics》2007,34(2):347-364
Abstract. The large deviation modified likelihood ratio statistic is studied for testing a variance component equal to a specified value. Formulas are presented in the general balanced case, whereas in the unbalanced case only the one-way random effects model is studied. Simulation studies are presented, showing that the normal approximation to the large deviation modified likelihood ratio statistic gives confidence intervals for variance components with coverage probabilities very close to the nominal confidence coefficient. 相似文献
135.
The diversity of potential relationships between child labor and health makes the empirical disentanglement of the causal
relationship a difficult exercise. This paper examines the long run impact of child labour on health by controlling for unobserved
household specific characteristics. In order to control for the unobserved households specific effect, we estimate a conditional
fixed effect model using data on siblings constructed from the Guatemalan National Survey of Living Condition. The estimation
results reinforce the conventional wisdom that child labor is harmful for health in the long run. The results can be interpreted
as a lower bound of the true impact since healthier children are most likely to offer themselves for employment and to be
appointed.
The views expressed in this paper are those of the authors and do not necessarily represent those of IMF and IMF policy. 相似文献
136.
杨燕 《淮海工学院学报(社会科学版)》2010,8(9):47-49
琵琶乐曲《十面埋伏》和《霸王卸甲》是大家熟悉的两首琵琶武曲,它们虽然在题材上、形式上有相似之处,可仔细比较起来却还是有许多差异。通过对创作特点,演奏特点和审美特点三方面的综合阐述,揭示了两首乐曲的内在联系和不同之处,便于欣赏者更好的了解两首古曲的动人之处。 相似文献
137.
N. T. Longford 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》1999,162(3):291-302
Missing data and, more generally, imperfections in implementing a study design are an endemic problem in large scale studies involving human subjects. We present an analysis of an experiment in the interaction between general practitioners and their patients, in which the issue of missing data is addressed by a sensitivity analysis using multiple imputation. Instead of specifying a model for missingness we explore certain extreme ways of departing from the assumption of data missing at random and establish the largest extent of such departures which would still fail to supplant the evidence about the studied effect. An important advantage of the approach is that the algorithm intended for the complete data, to fit generalized linear models with random effects, is used without any alteration. 相似文献
138.
常志有 《云南民族大学学报(哲学社会科学版)》2000,17(1):52-54
买方市场的形成是我国经济发展过程的一个划时代变化,它将对我国企业经营和营销带来严峻挑战。本文分析了我国买方市场的形成、特征及其对企业营销的影响,并就买方市场条件下企业营销对策进行了重点分析。 相似文献
139.
Tetyana Pudrovska 《Journal of marriage and the family》2008,70(1):168-181
Using data from 4,744 full, twin, half‐, adopted, and stepsiblings in the Wisconsin Longitudinal Study, I examine psychological consequences of motherhood and fatherhood in midlife. My analysis includes between‐family models that compare individuals across families and within‐family models comparing siblings from the same family to account for unobserved genetic and environmental endowments that may confound the relationship between parenthood and mental health. Further, I examine whether the psychological effect of parenthood varies among different types of sibling dyads. The findings reveal that parenthood has similar psychological implications for middle‐aged mothers and fathers. Main differences arise from specific configurations of the parental role. The association between parenthood and mental health partly reflects genetic influences but not shared early‐life environment. 相似文献
140.
泉州工商行政机关不断探索创新,在行政指导实践中取得明显成效,形成更多经验。为此追踪考察了泉州工商行政机关深入开展行政指导的基本做法,总结了泉州工商行政机关深入开展行政指导的成效和经验,就其继续深化工商行政指导实践提出若干对策建议。 相似文献